1. Elucidate the importance of Zeroth law of thermodynamics?
Ans:
This law signifies that temperature is a fundamental indicator of thermal equilibrium. If two bodies of the same temperature come in contact with each other then there is no net exchange of heat and those two bodies are said to be in thermal equilibrium.
2.Apply steady flow energy equation for a nozzle and State the assumption made. ?
Ans:
(i) The mass flow through the system remains constant. (ii) Fluid is uniform in composition. (iii) The only interaction between the system and surroundings are work and heat.
3.What is PMM2 and why is it impossible?
This is due to that some heat has to be rejected to sink. Therefore this heat engine violates the Kelvin-Planck statement of second law of thermodynamics. Hence it will be a perpetual motion machine of second kind (PMM2). PMM2 is impossible to produce
4.Differentiate clearly between the High Grade Energy and Low Grade Energy. ?
Ans:
High grade is that form of energy which completely converts into some other forms like electrical energy which can be converted into thermal energy but low grade energy will not be able to convert into other forms completely like thermal energy used in thermal power plants to convert into electricity.
5.Explain the P-T diagram for the heating process of water at constant pressure?
The phase diagram for most substances looks like this. ... Thus, the negative slope indicates that the liquid phase has a greater density than the solid phase. In other words, the density of ice is less than that of water. For most other common substances, the solid is denser than the liquid.
6.Draw the T-S and P-V diagram of an ideal Rankine cycle and explain
Ans:
7.Define Law of Corresponding states. ?
Ans:
According to van der Waals, the theorem of corresponding states (or principle/law of corresponding states) indicates that all fluids, when compared at the same reduced temperature and reduced pressure, have approximately the same compressibility factor and all deviate from ideal gas behavior to about the same degree.
8.What is Joule – Thomson coefficient? What does it signify?
Ans:The Joule Thomson coefficient is the ratio of the temperature decrease to the pressure drop, and is expressed in terms of the thermal expansion coefficient and the heat capacity.
9.State and prove the Dalton’s law of partial pressure ?
Ans:According to Dalton's law of partial pressures, the total pressure by a mixture of gases is equal to the sum of the partial pressures of each of the constituent gases. The partial pressure is defined as the pressure each gas would exert if it alone occupied the volume of the mixture at the same temperature.
10.What is adiabatic saturation temperature?
Ans:
Adiabatic saturation temperature is defined as that temperature at which water, by evaporating into air, can bring the air to saturation at the same temperature adiabatically. ... Air at the exit would be fully saturated and its temperature is equal to that of water temperature.
PART -B
11 . (A) :
A gas of mass 1.5 kg undergoes a quasi-static expansion which follows a
relationship P = a + bV, where a and b are constants. The initial and final
pressures are 1000 kPa and 200 kPa respectively and the corresponding
volumes are 0.20 m3 and 1.20 m3. The specific internal energy of the gas
is given by the relation, u = 1.5 Pv – 85 kJ/kg, where P is in kPa band v is
in m3/kg. Calculate the net heat transfer and the maximum internal
energy of the gas attained during expansion. ?
Ans:
